全文获取类型
收费全文 | 3050篇 |
免费 | 175篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 86篇 |
妇产科学 | 74篇 |
基础医学 | 428篇 |
口腔科学 | 337篇 |
临床医学 | 298篇 |
内科学 | 487篇 |
皮肤病学 | 46篇 |
神经病学 | 224篇 |
特种医学 | 83篇 |
外科学 | 370篇 |
综合类 | 8篇 |
一般理论 | 2篇 |
预防医学 | 365篇 |
眼科学 | 38篇 |
药学 | 203篇 |
中国医学 | 29篇 |
肿瘤学 | 119篇 |
出版年
2023年 | 25篇 |
2022年 | 42篇 |
2021年 | 97篇 |
2020年 | 80篇 |
2019年 | 96篇 |
2018年 | 125篇 |
2017年 | 77篇 |
2016年 | 82篇 |
2015年 | 106篇 |
2014年 | 168篇 |
2013年 | 154篇 |
2012年 | 287篇 |
2011年 | 252篇 |
2010年 | 160篇 |
2009年 | 111篇 |
2008年 | 215篇 |
2007年 | 199篇 |
2006年 | 146篇 |
2005年 | 160篇 |
2004年 | 134篇 |
2003年 | 110篇 |
2002年 | 96篇 |
2001年 | 39篇 |
2000年 | 30篇 |
1999年 | 32篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 17篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1976年 | 3篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1969年 | 4篇 |
1963年 | 2篇 |
1962年 | 3篇 |
排序方式: 共有3235条查询结果,搜索用时 15 毫秒
21.
Neves Lia Mara Grosso Tim Carla Roberta Floriano Elaine Medeiros da Silva de Avó Lucimar Retto Fernandes João Batista Parizotto Nivaldo Antonio Cominetti Marcia Regina 《Lasers in medical science》2021,36(4):863-870
Lasers in Medical Science - Ultraviolet radiation (UVR) is the major etiologic agent of cutaneous photoaging, and different strategies are used to prevent and treat this condition. The... 相似文献
22.
Daniela de Queiroz Moura Ramon Rawache Marília Ferreira Gomes Garcia Nathalia Farias Vasconcelos Priscila Santos Gustavo Rego Coelho Thiago Luis da Paz Santos Duílio Reis da Rocha Filho Sonia Leite da Silva Eliana Regia Barbosa de Almeida Paula F.C.B.C. Fernandes João Batista Cerqueira José Huygens Parente Garcia Claudia Maria Costa de Oliveira 《Transplantation proceedings》2021,53(4):1345-1349
Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation. 相似文献
23.
In vitro evidence for participation of DEC-205 expressed by thymic cortical epithelial cells in clearance of apoptotic thymocytes 总被引:2,自引:0,他引:2
Binding of apoptotic cells was compared after incubation of thymocytes with two clones of murine thymic stromal cells to which CD4(+)/CD8(+) thymocytes attach. With the BA/10, but not the BA/2, clone, thymocytes with apoptotic morphology were bound irreversibly. These tightly bound thymocytes were further identified as apoptotic in terms of active caspase-3 and DNA fragmentation assayed in situ. FACS analysis indicated that the apoptotic thymocytes are at an early double-positive stage and results with mice mutant for the Fas gene showed that the Fas-Fas ligand system is not involved. Comparison of BA/10 and BA/2 cells showed that the former, but not the latter, can be induced to express CDR-1 antigen which is characteristic of cortical epithelial thymic stroma and constitutively express DEC-205, a surface protein common to cortical thymic epithelium and dendritic cells. Antibody NLDC-145 that is specific for the DEC-205 protein strongly reduced the number of stromal cells with bound apoptotic thymocytes. Preincubation of thymocytes in dexamethasone dramatically increased the number of bound apoptotic cells, indicating that the thymic cortical epithelial cells can participate in clearance of apoptotic thymocytes through involvement of DEC-205. 相似文献
24.
The diterpenes ent-kaur-16-en-19-oic acid, ent-kaur-9(11),16(17)-dien-19-oic acid and 3 alpha-angeloiloxy-ent-kaur-16-en-19-oic acid were identified as trypanosomicidal compounds of the ethanolic extract from the aerial parts of Wedelia paludosa D.C. (Asteraceae), showing activity up to the lowest dose of 0.68 mg/mL in the in vitro assay against trypomastigotes of T. cruzi, the causative agent of Chagas' disease (American trypanosomiasis). The other isolates, friedelan-3 beta-ol, ent-kaur-16 alpha-ol-19-oic acid, beta-amyrin acetate and (22-E)-stigmasta-5,22-dien-3 beta-ol, were inactive. This is the first report on the trypanosomicidal activity of ent-kaur-9(11),16(17)-dien-19-oic acid and 3 alpha-angeloiloxy-ent-kaur-16-en-19-oic acids; this effect was already known for ent-kaur-16-en-19-oic acid. 相似文献
25.
Pharmacological evaluation of ricinine, a central nervous system stimulant isolated from Ricinus communis. 总被引:2,自引:0,他引:2
A C Ferraz M E Angelucci M L Da Costa I R Batista B H De Oliveira C Da Cunha 《Pharmacology, biochemistry, and behavior》1999,63(3):367-375
The extract of the pericarp of castor bean (Ricinus communis) showed some typical central nervous system stimulant effects when administered to mice. The animals became exophthalmic, presented tremors and clonic seizures and died a few minutes after receiving larger doses of the extract. At lower doses the extract improved memory consolidation and showed some neuroleptic-like properties, such as a decrease in exploratory behavior and catalepsy. The memory-improving effect and the seizure-eliciting properties of the extract were also observed with the administration of ricinine, a neutral alkaloid isolated from the extract. However, the neuroleptic-like properties of the extract were not observed with ricinine. As the therapeutic index of ricinine is of the order of 200, the compound may be considered as a promising cognition-enhancing drug that may be used for the treatment of human amnesias. 相似文献
26.
Oliva ML Andrade SA Batista IF Sampaio MU Juliano M Fritz H Auerswald EA Sampaio CA 《Immunopharmacology》1999,45(1-3):145-149
Kunitz type Bauhinia ungulata factor Xa inhibitor (BuXI) was purified from B. ungulata seeds. BuXI inactivates factor Xa and human plasma kallikrein (HuPK) with Ki values of 18.4 and 6.9 nM, respectively. However, Bauhinia variegata trypsin inhibitor (BvTI) which is 70% homologous to BuXI does not inhibit factor Xa and is less efficient on HuPK (Ki = 80 nM). The comparison between BuXI and BvTI reactive site structure indicates differences at Met59, Thr66 and Met67 residues. The hydrolysis rate of quenched fluorescence peptide substrates based on BuXI reactive site sequence, Abz-VMIAALPRTMFIQ-EDDnp (leading peptide), by HuPK and porcine pancreatic kallikrein (PoPK) is low, but hydrolysis is enhanced with Abz-VMIAALPRTMQ-EDDnp, derived from the leading peptide shortened by removing the dipeptide Phe-Ileu from the C-terminal portion, for HuPK (Km = 0.68 microM, k(cat)/Km = 1.3 x 10(6) M(-1) s(-1)), and the shorter substrate Abz-LPRTMQ-EDDnp is better for PoPK (Km = 0.66 microM, k(cat)/Km = 2.2 x 10(3) M(-1) s(-1)). The contribution of substrate methionine residues to HuPK and PoPK hydrolysis differs from that observed with factor Xa. The determined Km and k(cat) values suggest that the substrates interact with kallikreins the same as an enzyme and inhibitor interacts to form complexes. 相似文献
27.
Liz Girardi Müller Camila Simonetti Pase Patrícia Reckziegel Raquel C.S. Barcelos Nardeli Boufleur Ana Cristina P. Prado Roseane Fett Jane Mara Block Maria Amália Pavanato Liliane F. Bauermann João Batista Teixeira da Rocha Marilise Escobar Burger 《Experimental and toxicologic pathology》2013,65(1-2):165-171
The hepatoprotective activity of the aqueous extract of the shells of pecan nut was investigated against ethanol-induced liver damage. This by-product of the food industry is popularly used to treat toxicological diseases. We evaluated the phytochemical properties of pecan shell aqueous extract (AE) and its in vitro and ex vivo antioxidant activity. The AE was found to have a high content of total polyphenols (192.4 ± 1.9 mg GAE/g), condensed tannins (58.4 ± 2.2 mg CE/g), and antioxidant capacity, and it inhibited Fe2+-induced lipid peroxidation (LP) in vitro. Rats chronically treated with ethanol (Et) had increased plasmatic transaminases (ALT, AST) and gamma glutamyl transpeptidase (GGT) levels (96%, 59.13% and 465.9%, respectively), which were effectively prevented (87; 41 and 383%) by the extract (1:40, w/v). In liver, ethanol consumption increased the LP (121%) and decreased such antioxidant defenses as glutathione (GSH) (33%) and superoxide dismutase (SOD) (47%) levels, causing genotoxicity in erythrocytes. Treatment with pecan shell AE prevented the development of LP (43%), GSH and SOD depletion (33% and 109%, respectively) and ethanol-induced erythrocyte genotoxicity. Catalase activity in the liver was unchanged by ethanol but was increased by the extract (47% and 73% in AE and AE + Et, respectively). Therefore, pecan shells may be an economic agent to treat liver diseases related to ethanol consumption. 相似文献
28.
Caroline Louise Diniz Pereira Joelma Carvalho Santos Raissa Melo Arruda Milena Lima Rodrigues Eduardo Sampaio Siqueira Roberto Souza Lemos Andrea Dória Batista Ana Lúcia Coutinho Domingues Edmundo Pessoa Lopes 《Ultrasound in medicine & biology》2021,47(5):1235-1243
In patients with Mansoni schistosomiasis, it is fundamental to evaluate the disease morbidity, which is reflected by the severity of periportal fibrosis (PPF) and parameters of portal hypertension, as analyzed by ultrasonography (US). This study aimed to evaluate the morbidity of schistosomiasis by hepatic and splenic point shear-wave elastography (pSWE) and relate this to US parameters. The PPF pattern, the diameter of the portal and splenic veins and the size of the spleen were evaluated by US. Then, liver and spleen pSWEs were assessed in 74 patients using the same equipment. As the PPF pattern progressed, the splenic pSWE values significantly increased. Significant correlations between splenic pSWE, the longitudinal and transverse lengths of the spleen and the diameters of the portal and splenic veins were observed. These findings, however, were not observed through hepatic pSWE. In conclusion, the splenic pSWE has the potential for assessing morbidity in schistosomiasis mansoni. 相似文献
29.
30.